The sheriff said Hartwick had blocked two inside southbound lanes of the highway and was standing on the shoulder when he was struck by the front-loader, which was traveling about 20 mph. The deputy was killed instantly by the impact, according to investigators.
Gualtieri said the suspect continued driving for about a mile before stopping in a parking lot, where he told a co-worker he had hit a deputy and was going to flee the scene.
The sheriff's office said Hartwick's mother and two sons had been notified of his death while on duty. He was a 19-year veteran of the agency.
The suspect, Victor Vazquez-Real was captured Friday morning.